Starting yesterday it hasn't remembered where I'm at in any threads, unread button reverts to page 1 or a random page. Kind of a PITA on a years old topic with hundreds of pages. Happening again this evening, I was on earlier this evening then when I logged back on threads that I read earlier were marked unread again. Might be a chrome problem, but I haven't done anything to my chrome recently. I'll try FF on my 12 yr old Powerbook, haven't used it on TN for 2-3 years likely.
Same problem here on laptop/Firefox and on iphone. Mark all as read seems to correct this going forward.
I've been marking the forums as read for the last few days, still going to first or random pages when clicking the unread button.